Total and partial knee procedures involve affixing a femoral component to the end of a patient's femur, affixing a tibial component to the end of a patient's tibia, and inserting a orthopedic insert between the tibial component and the femoral component. The insert is typically formed of a plastic material that provides a surface against which the femoral component articulates. The orthopedic insert is typically inserted into the tibial component during surgery.
The locking features of current orthopedic inserts have a continuous contact region between the mating elements of the insert and the tibial component, which can create unwanted binding between the insert and the tibial component during insertion into the tibial component. The locking features often jam due to the relatively high manufacturing tolerances required to keep the insertion forces near 10-20 pounds of force, which requires tolerances of less than about 0.003 inches. Interference along any portion of the continuous contact region can prevent the insert from being properly seated in the tibial component. Moreover, if the locking features jam due to interference, the orthopedic insert can loosen in the patient and become detached from the tibial component.
Present knee implant systems limit the techniques available to surgeons during implant procedures. For example, the orthopedic insert is typically inserted into the tibial component from an anterior-to-posterior direction. It would be desirable to allow more flexibility in the way the orthopedic insert is aligned and then placed into the tibial component.